Semen Viability & “Semen Math”: Maximize Success with Fresh, Chilled & Frozen

Dr. Marty Greer returns to break down semen viability, the six parameters of semen analysis, practical “semen math,” and strategies for maximizing success with fresh-chilled and frozen semen.

Marty joins Laura to demystify semen viability and the practical realities of breeding with fresh, chilled and frozen semen. Whether you’re a first-time breeder or seasoned pro, this conversation delivers veterinary-backed guidance on how to assess semen quality, plan collections and protect valuable genetic material.

Key topics covered:

• Semen Math: Dr. Greer walks through the core formula: ejaculate volume × sperm concentration × percent motile × percent morphologically normal (× post-thaw survival for frozen samples) to determine total usable sperm and number of breeding units. Use this to decide when to freeze, how many straws/pellets equal a true breeding unit, and when to be conservative with limited inventory.
• Six parameters of semen analysis: ejaculate volume, gross appearance, sperm count, morphology, motility (directional swimming vs. circular or backward movement), and longevity. Why each matters and what incomplete reports (e.g., “plenty here”) really mean.
• Fresh vs. frozen considerations: why you shouldn’t “clean out” a male the night before collection; why freezing early (when the dog is young and virile) is critical; how older dogs and fragile semen tolerate freeze-thaw poorly; and breed- and individual-level variability in freeze tolerance.
• Practical troubleshooting for failed frozen breedings: confirm historic fertility, review original collection age/count/post-thaw stats, check packaging (straws vs. pellets) and breeding-unit definition, and discuss TCI vs. surgical options with your repro clinic.
• iSperm and accessibility: overview of affordable, tablet-based semen analyzers as a community tool for clinics and breeders to get reliable counts.
• Small, actionable tips: warming slides for motility checks, thermal risks to sperm, timing for clean-out collections, and using anti-inflammatory protocols that some clinics employ with compromised breedings.